"Hey Brian you are looking awfully nervous now, you are acting like you weren't doing magic so easily from before"
Artemis had nudged him a bit and Darius was sweating bullets, and Artemis knew something was up, but wasn't sure what it was.
Some time later at the main stadium for beast fighting in downtown opal city the guardians of magic were there and they were going to practice their powers properly now.
It wasn't until Artemis had unleashed his beast form and that "Brian" unleashed his beast form which was drastically different as it was a blood red manor with a horror vibe to it.
Everyone including Brian's older brothers were weirded out by this and Darius/Brian was frozen in fear, his magic had broken like glass before running away.